1. Field of the Invention
The present invention relates to an office chair, particularly to one that is formed in one-piece structure of plastic with an adjusting apparatus.
2. Description of the Related Art
A conventional office chair 10 as shown in FIGS. 1 and 2 comprises an underframe portion 11, a seat portion 12, a back portion 13 and two armrests 14, among which the seat portion 12 is the key to be composed with other components. The seat portion 12 of a conventional office chair 10 includes a metal plate 121 combining with a seat pad 122, and the bottom thereof combines a supporting device 123 to mount on a middle column 111 of the underframe portion 11. Besides, the metal plate 121 links up two connection seats 124 on both left and right sides to fix on the armrests 14. With such structure of multi components combination, the conventional office chair 10 is constructed in a complicated method whereby the finished product lacks unity and firmness, plus the heavy weight of metal materials; there is still room for improvements.
On the other hand, a conventional chair made of plastic has a lightweight advantage but the simple structure is more suitable for outdoor activities than offices.